The present invention relates to a novel fluoroelastomer composition, and more particularly to a fluoroelastomer composition suitable for preparing a fluoro-rubber having a low compression set and an excellent elastic property.
The term "fluoroelastomer" used herein means a highly fluorinated elastic copolymer and the term "fluoro-rubber" used herein means a cured copolymer obtained by curing the fluoro-elastomer.
A fluoro-rubber has an excellent heat resistance, a low temperature resistance and a chemical resistance and is useful for gaskets, sealants, diaphragmes, pipes and so on.
It is well known that fluoro-rubber is prepared by curing a fluoroelastomer in the presence of curing agent. The fluoro-rubber is required to have an excellent elastic property as well as a low compression set in the practical uses. In general, however, a fluoro-rubber prepared by curing a conventional composition tends to be inferior in compression set when the elastic property is guaranteed and, on the other hand, tends to reduce its elastic property when compression set is suppressed. Therefore, a fluoroelastomer composition which is able to provide a fluoro-rubber having an excellent elastic property in addition to a low compression set is earnestly desired.
Recently, various fluoroelastomer composition which can be cured to provide fluoro-rubbers having a low compression set have been proposed. These fluoroelastomer compositions are somewhat effective for reducing compression set, but it tends to have poor elastic property.